Remote-cutting - a smart solution using the advantages of high brightness lasers

Laser cutting plays a huge role in the field of laser materials processing. An excellent beam quality, a great laser power and a high absorption rate are the most important ones in order to reach high cutting speeds in combination with high cutting edge qualities. Providing the mentioned characteristics, the fibre laser has the biggest potential. Studies at Fraunhofer IWS have shown, that cutting with fibre lasers is promising in order to reach high cutting rates and cutting edge qualities (1)(2)(3). Beam qualities below 2.5 mm mrad at a wavelength of about 1 my m and a laser power in the area of several kW enable new possibilities in laser processing. With such characteristics it is possible to cut thin sheets with very high cutting rates. However, these cutting speeds cannot be achieved with linear drives, especially in the case of cutting contours. Thus the cutting speeds are currently limited by the dynamic of the used handling system. Cutting speeds limited by the ability of the laser are much higher. A solution to minimize this gap is described in the presented research paper. This paper describes a smart solution using the advantages of high brightness lasers - the remote cutting. Firstly a short introduction of the process is given and the experimental equipment will be explained. Disclaiming any cutting gas a nozzle is no longer necessary. Thereby the working distance does no longer depend on the distance between the nozzle and the work piece. In combination with a 2D-Scanner the laser beam is flexible in the working field of the scanner. Afterwards a thermodynamic characterization of the remote cutting process is carried out. The investigations show a process, which is completely different from conventional laser cutting. The cutting kerf is generated by a layer by layer ablation process. However, an example shows that contour cutting speeds of about 100 m/min are possible.